(a) Field of the Invention
The present invention relates generally to data delivery and, more particularly, to a method and apparatus for delivering Internet newsgroup information over a broadcast network.
(b) Description of Related Art
Internet newsgroup services are known. Network news started as mailing lists on the ARPANET and then grew into the Usenet news system. As will be apparent to those skilled in the art Usenet is a news service (see e.g., www.interactive.net/netnews). Mailing lists are still popular today, but in terms of sheer volume, network news has grown rapidly over the past decade.
Usenet is not a physical network, but a logical network implemented on top of many different types of physical networks. Years ago the popular way to exchange network news on Usenet was with dial-up phone lines (normally during off-peak hours to save money), however, today the Internet is the basis for most news distribution.
The Usenet news system supports thousands of different newsgroups. Each newsgroup is identified by a newsgroup name that identifies the topic of discussion carried on the newsgroup. Newsgroups are available for a vast array of different topics ranging from business and technology to cooking. Newsgroups also cover a-variety of controversial topics. Accordingly, a user may strongly desire to keep private, the newsgroups he or she has accessed. A user may post an article to one or more newsgroups. The article is then distributed to news servers throughout the Internet so it can be accessed by other users. An article is a text message often with attachments such as pictures, audio segments or some other binary data. Articles without attachments are typically less than 10,000 bytes in length. However, articles with attachments may range between 20,000 and 80,000 bytes in length. As of September 1998, the Usenet news system carries 10,000 to 15,000 MB of new articles every day. These articles are posted to roughly 30,000 different newsgroups. This is equivalent to more than 1.5 Mbps of new articles per day, on average.
FIG. 1 is an overview of a typical news setup. An Internet Service Provider (ISP) configures one host as the ISP""s news server and stores all recently posted news articles locally. News servers are organized into a logical network across the Internet, feeding news articles to each other. The Network News Transfer Protocol (NNTP) is used for communication between news servers. NNTP is an application protocol, as described in Request for Comment (RFC) 977, used for the distribution, inquiry, retrieval, and posting of news articles using a reliable stream-based protocol, such as Transmission Control Protocol (TCP). TCP is described in RFC 793. News articles use various header fields as documented in RFC 1036. News servers may be implemented in various ways, for example, InterNetNews (INN) is a popular UNIX news server application.
An ISP""s subscribers, often Personal Computers (PCs) having dial-up connections into the Internet, access the news server to read news articles and post new articles to selected newsgroups. Subscribers use xe2x80x9cnews clientsxe2x80x9d or xe2x80x9cnewsreadersxe2x80x9d to communicate with the news server, via NNTP. Many news clients, such as Microsoft Internet News(trademark), Microsoft Outlook Express(trademark) and Netscape Communicator""s Collabra(trademark) application are commercially available. Each news client presents a different user interface, similar to the multitude of different user interfaces presented by various email client programs. News clients interact with the newsgroup server to:
1. Retrieve the list of newsgroups maintained by the news server.
2. Retrieve the titles of articles within the news server posted to a specific newsgroup.
3. Retrieve all the articles posted to a specific newsgroup.
4. Post an article to one or more newsgroups.
A news client often allows a user to xe2x80x9csubscribexe2x80x9d to one or more newsgroups. The news client then automatically downloads any new articles from the subscribed-to newsgroups, thereby allowing the downloaded articles to be viewed later, perhaps when the user is not connected to the Internet. All news clients use NNTP to communicate with the news servers.
News servers are organized into a xe2x80x9cstore and forwardxe2x80x9d network. When a client posts an article, a news server stores a copy and forwards the article to a configurable set of news servers. These news servers, upon receiving an article from another news server, store a copy if the article was not previously stored and forward the article to other news servers so that eventually an article is forwarded to all news servers. Using the store and forward technique ensures that an article will be forwarded to all news servers on the Internet that are interested in storing newsgroups to which the article was posted.
As previously noted, newsgroup articles may be quite large. When the user subscribes to many newsgroups or to newsgroups where the articles typically have large attachments, it may take a user a long time to download articles to the user""s PC from the news server. This is inconvenient to a user as he/she must wait to access and read the articles. Additionally, each subscriber""s newsgroup subscriptions must be communicated to that subscriber""s ISP, thereby eliminating the privacy of newsgroup subscriptions.
The present invention is embodied in an apparatus and method for providing newsgroup information to a plurality of users. The present invention includes a transmitter for receiving the newsgroup information from one or more servers and for formatting the newsgroup information into newsgroup packets for multicast over a multicast network such as a digital geosynchronous satellite IP multicast system.
In an another embodiment, the present invention includes a personal news server for receiving and processing multicast newsgroup packets to recover newsgroup information and storage media for storing the newsgroup information.
In another embodiment, the present invention includes a downstream news server for receiving and processing multicast newsgroup packets and to make the stored newsgroup articles available to clients via a network interface.
The present invention may also be embodied in an apparatus for receiving newsgroup packets and relaying them to one or more servers according to the NNTP protocol, such invention including a Usenet relay server for receiving and processing multicast newsgroup packets to recover newsgroup information, storage media for storing the newsgroup information, and a network interface for relaying the newsgroup information to the news servers.
The invention itself, together with further objects and attendant advantages, will best be understood by reference to the following detailed description, taken in conjunction with the accompanying drawings.